Cecily. May I offer you some tea, Miss Fairfax?Gwendolen. [With elaborate politeness.] Thank you. [Aside.] Detestable girl! But I require tea!Cecily. [Sweetly.] Sugar?Gwendolen. [Superciliously.] No, thank you. Sugar is not fashionable any more. [Cecily looks angrily at her, takes up the tongs and puts four lumps of sugar into the cup.]Cecily. [Severely.] Cake or bread and butter?Gwendolen. [In a bored manner.] Bread and butter, please. Cake is rarely seen at the best houses nowadays.Cecily. [Cuts a very large slice of cake, and puts it on the tray.] Hand that to Miss Fairfax. [Merriman does so, and goes out with footman. Gwendolen drinks the tea and makes a grimace. Puts down cup at once, reaches out her hand to the bread and butter, looks at it, and finds it is cake. Rises in indignation.]Gwendolen. You have filled my tea with lumps of sugar, and though I asked most distinctly for bread and butter, you have given me cake. I am known for the gentleness of my disposition, and the extraordinary sweetness of my nature, but I warn you, Miss Cardew, you may go too far.Cecily. [Rising.] To save my poor, innocent, trusting boy from the machinations of any other girl there are no lengths to which I would not go.

Algernon. If it was my business, I wouldn’t talk about it. [Begins to eat muffins.] It is very vulgar to talk about one’s business. Only people like stock-brokers do that, and then merely at dinner parties.Jack. How can you sit there, calmly eating muffins when we are in this horrible trouble, I can’t make out. You seem to me to be perfectly heartless.Algernon. Well, I can’t eat muffins in an agitated manner. The butter would probably get on my cuffs. One should always eat muffins quite calmly. It is the only way to eat them.Jack. I say it’s perfectly heartless your eating muffins at all, under the circumstances.Algernon. When I am in trouble, eating is the only thing that consoles me. Indeed, when I am in really great trouble, as any one who knows me intimately will tell you, I refuse everything except food and drink. At the present moment I am eating muffins because I am unhappy. Besides, I am particularly fond of muffins. [Rising.]Jack. [Rising.] Well, that is no reason why you should eat them all in that greedy way. [Takes muffins from Algernon.]Algernon. [Offering tea-cake.] I wish you would have tea-cake instead. I don’t like tea-cake.Jack. Good heavens! I suppose a man may eat his own muffins in his own garden.Algernon. But you have just said it was perfectly heartless to eat muffins.Jack. I said it was perfectly heartless of you, under the circumstances. That is a very different thing.Algernon. That may be. But the muffins are the same. [He seizes the muffin-dish from Jack.] …..….. Jack. [Picking up the muffin-dish.] Oh, that is nonsense; you are always talking nonsense.Algernon. Jack, you are at the muffins again! I wish you wouldn’t. There are only two left. [Takes them.] I told you I was particularly fond of muffins.Jack. But I hate tea-cake.Algernon. Why on earth then do you allow tea-cake to be served up for your guests? What ideas you have of hospitality!Jack. Algernon! I have already told you to go. I don’t want you here. Why don’t you go!Algernon. I haven’t quite finished my tea yet! and there is still one muffin left. [Jack groans, and sinks into a chair. Algernon still continues eating.]

Because the men fight over food the most (Algernon’s wolfing down of the cucumber sandwiches to Lady Bracknell’s distress, Jack’s settling for bread and butter, Algernon’s consumption of Jack’s wine and muffins), we suspect that food fights are their way of expressing their sexual frustration in the face of unusually domineering women. (source)

On one level, the jokes about food provide a sort of low comedy, the Wildean equivalent of the slammed door or the pratfall. On another level, food seems to be a stand-in for sex, as when Jack tucks into the bread and butter with too much gusto and Algernon accuses him of behaving as though he were already married to Gwendolen. Food and gluttony suggest and substitute for other appetites and indulgences. (source)